Leno was an odd success. He was a consistent ratings winner, yet was never exactly loved by the viewing audience. His unlovable side lurked near the surface. After out-manoeuvring David Letterman for the Tonight host job, Leno fired his long-time manager Helen Kushnick as Tonight Show executive producer four months in.

He was obsessed with the press and seemingly read everything anybody wrote about him (in the ‘90s, pre-Google). Leno once phoned the Toronto Sun after then TV critic Claire Bickley had interviewed a Canadian Tonight Show intern, who claimed to have written a joke that was used on-air. “(Leno) denied he ever used the intern’s joke,” Bickley recalls. “He was quite livid about it, very angry. I wondered why he wouldn’t just let it go. That call was like using a jackhammer to kill a gnat.”

But it was his fellow comics who fell out of love the hardest. From early complaints that he was stingy with the time allotted to comics on his show, to the widespread opinion that the once-edgy Leno had softened his persona to mush, to vicious public feuds with the likes of Jimmy Kimmel and George Lopez, Leno lost the cachet he once had as a Comedy Store pioneer and comic’s comic.

No one knows where the Lopez feud started, but at Montreal’s Just For Laughs Festival in 2007 he told us simply, “I hate him,” when asked about Leno. The hard feelings deepened after Leno approached someone he thought was Lopez at a party, intending to mend fences. It turned out to be Paul Rodriguez, another Chicano-American comic.

“That is the kind of guy he is,” Lopez said. “He’s known Paul Rodriguez for 25 years. There’s people who think he’s a f---in’ a-----, and I’m one of them. He can spend the rest of his life wondering why people don’t like him.”

Andy Kindler is famous for his State Of The Industry Address every year at Just For Laughs. His regular targets at the roast-like event include Leno, who he says, “is in the Guinness Book of Records for going the longest time without an authentic moment.”

A few years ago, Kindler said, “Leno’s car broke down near where my wife was living at the time. I looked at his car and tried to walk past him, and he said, ‘That’s the guy who hates me!’ He really does know everything that people say about him.”

But it was Kimmel who said it to his face. When Leno still had his 10 p.m. NBC show, but the announcement had been made to boot Conan from Tonight and put Leno back in the chair, Kimmel came on as a guest.

Asked about his favourite prank, Kimmel told Leno acidly, “I told a guy, ‘Five years from now, I’m going to give you my show.’ And then when the five years came, I gave it to him, and then I took it back almost instantly.”

Later in the interview, Kimmel said, “Listen, Jay, Conan and I have children. All you have to take care of is cars. We have lives to lead here. You have $800 million. For God’s sake, leave our shows alone!”